The Bush administration said Monday nearly all members of the International Atomic Energy Agency governing board share U.S. concerns about Iran's nuclear program. The IAEA board began a meeting in Vienna Monday expected to produce a resolution calling on Iran to comply with commitments under the Nuclear Non-Proliferation Treaty.

The Bush administration has been engaged in intensive contacts with other member countries of the IAEA board on the Iranian nuclear program, which U.S. officials believe is hiding a secret nuclear weapons project.

And as the 35-nation board began a week-long session in Vienna, officials here were saying they expect the meeting to yield a resolution strongly critical of Iran.

At a news briefing, State Department spokesman Richard Boucher said there is "compelling evidence" from the IAEA that Iran has been trying to "hide and deny nuclear activities" and has refused to cooperate fully with inspectors, and he said U.S. concerns are widely shared by other board members.

"From our discussions to date, we believe that almost all members of the International Atomic Energy Agency Board share our grave concerns about Iran's activities, fully support the International Atomic Energy Agency's ongoing efforts to uncover the truth of Iran's programs, and agree that Iran must urgently take steps to cooperate fully and answer all outstanding questions," he said.

An IAEA report last month said traces of weapons-grade enriched uranium were found at a mostly-underground enrichment plant in central Iran, the existence of which was disclosed last year by an Iranian exile group.

As the IAEA meeting began, the agency director-general Mohammed El-Baradei said information provided by Iranian authorities has been slow in coming and piecemeal.

He called on Tehran to, among other things, resolve outstanding questions about its enrichment effort and accept additional safeguards under the Non-Proliferation Treaty.

Mr. Boucher said there is a "considerable consensus" among board members that Iran needs to support efforts by the agency to "uncover the truth" about the program.

He said the United States is seeking to build support for the "strongest possible" resolution from the board demanding Iranian compliance, and continues to believe the matter should be taken up by the U.N. Security Council "at the appropriate time."

News reports from Vienna quoted diplomats as saying U.S. officials dropped the idea of an immediate referral to the Security Council because of a lack of support, but appeared to have the votes for an IAEA resolution demanding "urgent and essential cooperation" by Iran with agency inspectors.

Iran, a member of the IAEA board, denies having nuclear weapons ambitions and says the enrichment plant was built to support a peaceful power-generation program.